1. Field of Invention
This invention relates to optical scanners and, more particularly, to a bar code wand reader adapted to read a bar code disposed on a curved surface.
Wand readers for scanning a bar code label are well known to those skilled in the art. Such a pen-shaped wand is commonly used to input data contained in printed bar code labels affixed to selected goods to an attached computer system. Such a bar code provides a method of coding the data such that it will represent the necessary numerical characters needed to identify the product being scanned.
Although such wand readers are well suited to use with products whereon the bar coded label may be fixed to a flat surface, a problem arises when attempting to attach such bar coded labels to a relatively small curved surface. Because the wand reader must be passed over the bar code at a relatively fast and constant speed, the degree of muscle control required to perform this task on a small curved surface makes it difficult to get a proper reading and numerous passes are almost invariably required to do so.
Thus, the present invention has been developed to provide a simple yet efficient device to enable a standard wand reader to be used to scan a bar coded label on a small curved surface.
2. Description of Related Art
U.S. Pat. No. 5,231,278 to Ming-Tai D. Kuo discloses a bar code wand reader adapted to read a bar code disposed on a narrow surface such as an edge of a printed wiring board.
U.S. Pat. No. 5,300,762 to Robert L. Roske discloses a shoe adapter for a bar code wand which frictionally engages a portion of the scanning head of the wand and maintains the wand at a consistent distance from the bar code label.
U.S. Pat. No. 5,373,165 to William A. Willson discloses a guide for mounting on an optical scanner having a laterally extending guide arm whereby the scanner can be moved in a parallel relationship with a straight edge to prevent lateral movement of the scanner for superior scanning capability.
U.S. Pat. No. 3,818,188 to Guther Hertel, et al. discloses a device for positioning a data carrier in a reading apparatus, the data carrier being attached, for example, to a test tube by means of a coupling element.
U.S. Pat. No. 4,457,016 to George B. Pfeffer discloses a file label reading system including a manually controlled wand which is adapted by the provision of a jig used to bear against the edge of at file for locating the wand in a read position over the bar code to steady the manual movement of the wand in order to provide an accurate reading of the code.
U.S. Pat. No. 4,210,802 to Toshiyasu Sakai discloses a bar code scanner having a pair of parallel side guide members connected by a transverse guide number which defines a scanning line at the end portions of the parallel side guide members.
U.S. Pat. No. 4,463,251 to Pauli Koutonen, et al. discloses a method for the identification of paper rolls by means of a code attached to or marked on the end surface of the roll. The code is read by a combined signal optical beam transmitter-receiver, including a guide arm which serves to locate the scanner in the center of the paper roll to provide an accurate reading.
Finally, U.S. Pat. No. 3,413,447 to Herbert La Mers discloses an information bearing label and method of reading the same which utilizes a wand reader having a center probe for locating the wand relative to a radially arranged bar code.